The present invention relates to a compound containing an oxamic acid group which has both the properties of high reactivity and high stability for water and, in particular, to a compound containing an oxamic acid group which is, as a material having a new function, usable as paints, adhesive agents, plastic materials, and the like in a form of reaction material or resin, in addition, to a process for producing the compound, and to a resin composition containing the compound.
In a case of that coating by a resin in an organic system is carried out in a water medium, it is required to lower viscosity of a solution of the resin to facilitate coating by a physical method and thus, a technique to dissolve or disperse the resin in an organic system becomes important.
The dissolving and/or dispersing of the resin in an organic system are possible by a quality improvement (character change) of the resin with introduction of a hydrophilic group and/or an ionic functional group in a part of the resin molecule and/or by dispersion of the resin with use of a surface active substance having a hydrophilic and/or an ionic functional group, but there has been widely used a method where the ionic functional group is introduced in a part of the resin.
This ionic functional group contributes for dispersion and stabilization of the resin into water in a stage of that the resin is in a paint condition, as described above, and then in a process of coating followed by resin-hardening, sometimes displays a function of an acid catalyst for hardening and, furthermore, can give a crosslinking structure by reacting with a functional group of other hardening agents. However, the functional group remaining in a hardened paint film causes lowering in water-resisting and anticorrosion properties and in durability of the paint film.
If an example is cited, in an anionic resin for electrodeposition, while an ionic functional group such as a carboxyl group shows an anionic character and contributes for stabilization of a resin-dispersing solution, it contributes for separating resin on a plate by being neutralized on turning of an electric current. However, in a stage of a paint film having been hardened with heating, the remainder of said carboxyl group etc. lowers anticorrosion and water-resisting properties of the paint film. Furthermore, a carboxyl group etc. remaining during a hardening time, since it has an anionic character, may lower reactivity of the agent in a case of that a hardening agent such as an isocyanate etc. is used.